抗稳定同位素解读PM2.5-bound抗源来源和在喜马拉雅大气中的跨界运输
Chenmeng Yang1,2, Guangyi Sun1,3, Yunjie Wu1
1State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
Environmental science & technology
|December 31, 2025
概括
喜马拉雅空气中的反污染受南亚煤炭和生物质燃烧的影响,沙漠尘埃也在其中发挥作用. 季风雨影响污染物运输,突出了高海拔生态系统的跨境风险.
科学领域:
- 环境科学 环境科学
- 大气化学 大气化学
- 同位素地球化学 同位素地球化学
背景情况:
- (Sb) 是一种致癌污染物,在细颗粒物 (SbPM2.5) 中发现.
- 在喜马拉雅山脉等脆弱地区,SbPM2.5的来源和跨境运输尚未得到充分了解.
- 高海拔的生态系统特别容易受到大气污染的影响.
研究的目的:
- 在西藏高原的科蒙朗玛山站 (QOMS) 确定SbPM2.5的来源和季节性传输机制.
- 调查跨境污染对喜马拉雅大气的影响.
- 评估季风动力学在大气中反运输中的作用.
主要方法:
- 在全年空气样本中对抗氧稳定同位素 (ε123Sb) 的分析.
- 空气质量轨迹分析以确定运输路径.
- 多变量混合建模采用Sb同位素和Rb/Sr比率来量化源贡献.
主要成果:
- 在QOMS的年平均SbPM2.5度与欧洲城市地区相当,这表明具有显著的跨境影响.
- Sb同位素标志显示季节性,较轻的值与南亚煤炭燃烧和生物质燃烧有关,较重的值与沙漠尘埃有关.
- 一个混合模型确定了沙漠尘埃 (23-64%),煤炭燃烧 (13-46%) 和生物质燃烧 (14-45%) 作为主要来源,受西方循环和冰川谷风的影响.
- 季风降水通过湿清理调节同位素组成.
结论:
- 这项研究是第一个使用Sb同位素来追踪大气中的Sb在高海拔地区的研究.
- 证明了季风调节的运输和来自南亚的占主导地位的人为信号.
- 研究结果为高海拔生态系统的跨境重金属污染提供了关键的见解,并为缓解策略提供了信息.
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